A drift amount computing device (100) computes an amount of drift between a first image and a second image, and comprises a correlation function computing section (112) for calculating a correlation function between the first and second images, a local maximum position searching section (114) for searching a range of positions of the correlation function for local maximum positions, a local maximum position determining section (116) for assigning weights to intensities of plural local maximum positions according to the distance from the center of the correlation function, comparing the weighted intensities of the local maximum positions, and determining one of the maximum local positions which corresponds to the amount of drift, and a drift amount computing section (118).

A method of determining a distortion of a field of view of a scanning electron microscope is described. The method may include: providing a sample including substantially parallel lines extending in a first direction; performing scans across the field of view of the sample along respective scan-trajectories extending in a scan direction; the scan direction being substantially perpendicular to the first direction; detecting a response signal of the sample caused by the scanning of the sample; determining a distance between a first line segment of a line and a second line segment of the line, whereby each of the first line segment and the second line segment are crossed by scan trajectories, based on the response signal; performing the previous step for multiple locations within the field of view; and determining the distortion across the field of view, based on the determined distances at the multiple locations.

In one embodiment, a method for inspecting a blanking plate includes generating a plurality of beams by causing a charged particle beam to pass through a shaping aperture array having a plurality of holes, performing blanking deflection on the plurality of beams by using a plurality of blankers provided in a blanking plate, each of the plurality of blankers corresponding to one of the plurality of beams, writing a first inspection pattern on a substrate by using a first writing mode in which beams that have not been deflected by the plurality of blankers are radiated onto the substrate, writing a second inspection pattern on the substrate by using a second writing mode in which beams that have been deflected by the plurality of blankers are radiated onto the substrate, obtaining a pattern image of the first inspection pattern and a pattern image of the second inspection pattern, the first and second inspection patterns having been formed on the substrate, and determining a defect by comparing the obtained pattern images.

A scanning electron microscope incorporates a multi-pixel solid-state electron detector. The multi-pixel solid-state detector may detect back-scattered and/or secondary electrons. The multi-pixel solid-state detector may incorporate analog-to-digital converters and other circuits. The multi-pixel solid state detector may be capable of approximately determining the energy of incident electrons and/or may contain circuits for processing or analyzing the electron signals. The multi-pixel solid state detector is suitable for high-speed operation such as at a speed of about 100 MHz or higher. The scanning electron microscope may be used for reviewing, inspecting or measuring a sample such as unpatterned semiconductor wafer, a patterned semiconductor wafer, a reticle or a photomask. A method of reviewing or inspecting a sample is also described.

The present disclosure relates to an apparatus and methods for generating a hybrid image by high-dynamic-range counting. In an embodiment, the apparatus includes a processing circuitry configured to acquire an image from a pixelated detector, obtain a sparsity map of the acquired image, the sparsity map indicating low-flux regions of the acquired image and high-flux regions of the acquired image, generate a low-flux image and a high-flux image based on the sparsity map, perform event analysis of the acquired image based on the low-flux image and the high-flux image, the event analysis including detecting, within the low-flux image, incident events by an event counting mode, multiply, by a normalization constant, resulting intensities of the high-flux image and the detected incident events of the low-flux image, and generate the hybrid image by merging the low-flux image and the high-flux image.

A control unit for generating a timing signal for an imaging unit in an inspection system in which an image of an inspection target object is captured by the imaging unit while the inspection target object is caused to travel in a predetermined direction includes a traveling distance determination section configured to detect a traveling distance of the inspection target object based on a count value acquired as an integer value from a laser interferometer provided in the inspection system for detecting a traveling distance of the inspection target object, and configured to determine whether the detected traveling distance reaches a threshold, and a timing signal generation section configured to generate a timing signal when it is determined that the detected traveling distance reaches the threshold. The traveling distance determination section executes the determination by using a plurality of values selectively as the threshold.

A method for automatically imaging in an electron microscope (SEM, TEM or STEM) features in a region of interest in a lamella without prior knowledge of the features to be imaged, thereby enabling multiple electron microscope images to be obtained by stepping from the first image location without requiring the use of image recognition of individual image features. By eliminating the need for image recognition, substantial increases in image acquisition rates may be obtained.

A secondary projection imaging system in a multi-beam apparatus is proposed, which makes the secondary electron detection with high collection efficiency and low cross-talk. The system employs one zoom lens, one projection lens and one anti-scanning deflection unit. The zoom lens and the projection lens respectively perform the zoom function and the anti-rotating function to remain the total imaging magnification and the total image rotation with respect to the landing energies and/or the currents of the plural primary beamlets. The anti-scanning deflection unit performs the anti-scanning function to eliminate the dynamic image displacement due to the deflection scanning of the plural primary beamlets.

An etch process performed during semiconductor processing is monitored using a resonant structure on a surface of a wafer, formed on the surface of a wafer as a resonant cavity. A resonance sensor is positioned over the wafer within a plasma etch chamber so as to establish a resonance with the resonant structure. A resonant frequency of the resonant structure is sensed through the resonant structure and shifts in the resonant frequency are thereby detected during an etch process as a measurement of the etch process. The etch process is controlled in accordance with the shift in the resonant frequency.

A substrate processing tool capable of detecting a gap and/or shifting of a substrate clamped to a clamping surface in a processing chamber based on observed behavior of RF power delivered to the processing chamber during processing. The behavior of the RF power is observed by comparing a voltage-current phase angle difference and/or impedance magnitude change between a real RF power component and a reactive RF power component of the RF power delivered to the processing chamber.